Recently, with the improvement of economic conditions, many people have had the means to travel abroad to see the longed-for landscapes with their own eyes and take pictures of the beauty in sight with the smartphones or digital still cameras they carry with them as a souvenir to remember the scenery by. However, a series of photos taken of the same site can never compare to a “panoramic photo”, which can record the grandeur of a magnificent view more realistically than separate photos.
As smartphones and digital still cameras become more and more affordable, there is almost no tourist without one. Thanks to the plethora of image editing software on the market, many people have also learned to combine a series of photos taken of the same site into a panoramic photo using such software, in order to show the indescribable beauty they witnessed on their journeys. Today, many smartphones and digital still cameras have a “panorama function” by which to take panoramic photos. A user only has to switch the smartphone or digital still camera at hand to the “panorama mode” and perform a “horizontal scanning” operation, and a panoramic photo will be produced via the image processing software installed in the smartphone or digital still camera. A panoramic photo thus produced, however, has poor image quality when magnified. The two main reasons are as follows. First, the images taken by a smartphone or digital still camera are in the JPG format and therefore far less delicate than those in the RAW format. Second, some smartphones and digital still cameras do not provide high image resolution, so the images they take do not include as many details as desired. If, therefore, a digital single-lens reflex camera is used to take high-quality photos of a scenic spot, and the photos are then rendered into a fine panoramic photo, the details of the latter photo must be overwhelming when viewed magnified. It is this kind of panoramic photos that deserve to be kept for a lifetime.
But how to produce such an overwhelming panoramic photo? It must be understood in the first place that a panoramic photo of high image quality is in fact an assembly of a number of photos. More specifically, a plurality of photos are taken horizontally and consecutively of the same scenic spot and then sequentially stitched together using suitable image editing software (e.g., Photoshop). Take a common digital single-lens reflex camera for example. As the view angle of the lens is generally 60 degrees, at least eight photos must be taken in order to produce a 360-degree panoramic photo of high image quality. Basically, the more photos are stitched together, the better the result. When producing a 360-degree panoramic photo, referring to FIG. 1, it is crucial that each constituent photo has an appropriate portion reserved as an “overlap area”, and the larger the overlap area, the better the stitching result. This is especially true when a lens of a relatively short focal length (e.g., 18 mm, 28 mm, etc.) is used, for it is difficult to stitch together photos with a strong sense of perspective, and a more natural stitching result can be obtained in that case by taking more photos and making the overlap area as large as possible. To ensure that a 360-degree panoramic photo has high image quality, therefore, it is common practice to take more than ten or even dozens of photos of the same site in a horizontal and consecutive manner, then adjust the brightness and colors of each photo with suitable image editing software in order to achieve consistency in brightness and hue, then stitch together the overlap areas of each two adjacent photos with the image editing software, and finally trim the sides of the stitched-together photo with the cutting tool of the image editing software in order to obtain the desired high-quality 360-degree panoramic photo.
While the foregoing process of taking a series of photos horizontally and successively of the same site and stitching the photos together with image editing software is already a technique frequently used by a few professional photographers to make high-quality 360-degree panoramic photos, an amateur may, even under the guidance of a professional photographer, find it difficult to determine the number of photos to be taken and the size of the overlap areas, not to mention the complicated editing process that follows, including adjusting the brightness and colors of each photo, stitching the photos together, trimming the composite photo, and so on. It is truly a shame that only few people are capable of using image editing software to combine a series of photos taken horizontally and sequentially of a scenic spot into a 360-degree panoramic photo of high image quality.
Accordingly, the issue to be addressed by the present invention is to design a method for producing a panoramic photo by a stitching process, allowing a user to take at least two photos and then apply the stitching process to stitch the photos rapidly and precisely together to form a 360-degree panoramic photo of high image quality.